The present invention relates to a screening method, a screening device and a program, and particularly to a screening method, a screening device and a program which respectively measure the characteristics of semiconductor devices and detect outliers in the characteristics to thereby screen the semiconductor devices.
A screening device suitable for semiconductor devices is used to detect defects inherent in the semiconductor devices and screen the semiconductor devices. A screening device described in, for example, a Patent Document 1 observes physical quantities of semiconductor devices on a wafer, inspects distributions of the physical quantities to identify semiconductor devices indicative of physical quantities (i.e., outliers or abnormal values) that deviate from the distributions, thereby performing their screening. Such a technique is also called outlier screening.
FIG. 12 is a block diagram showing a configuration of the screening device described in the Patent Document 1. Semiconductor devices fabricated over each wafer 4 are electrically coupled to an LSI tester 1 through a prober 2. Thus, various physical quantities of the semiconductor devices are measured. The measured physical quantities are stored in a data file 3 along with information for identifying the semiconductor devices. A computer 5 calculates respective distributions of the measure physical quantities and identifies semiconductor devices indicating physical quantities that deviate from the distributions respectively.
There has been described in a Patent Document 2, a semiconductor testing method which selects a semiconductor chip determined to be a non-defective product as a target for determination, defines a calculation range of predetermined sizes around the selected semiconductor chip, generates an electrical characteristic distribution in the calculation range using the electrical characteristics of each semiconductor chip determined to be a non-defective product, of semiconductor chips included in the calculation range, and determines whether the selected semiconductor chip falls outside the prescription in the electrical characteristic distribution.